In many districts, including Hillsboro, North Clackamas, Salem and Eugene, the change is astounding. Last year, nearly every kindergarten class in those districts lasted two hours and 45 minutes. Now, every single one will run all day.

The change is one Oregon educators advocated for years, citing Oregon's stubbornly low rate of third-graders who can read at grade level – just 66 percent in 2013 and 2014 – and a growing body of research about brain development in young children.

Educators say full-day is qualitatively different from half-day, not just longer. Lessons go deeper. There's more time to build classroom routines and self-management skills. Art, music and science get more attention. And kindergartners get a real chance for hands-on exploration.

At John McLoughlin Elementary in Oregon City this week, Allison Haycraft's kindergartners got to investigate density on their first full day together. Five-year-old Trenton Patterson reacted with amazement when, as he had tentatively predicted, a popsicle stick floated when he placed it in water.

"It floated! It really floated!" he exclaimed. The sinking of a paper clip and the floating of a cotton ball only amplified his excitement.

State funding of the program has given schools and families new options. That's true even in Portland Public Schools, which phased out half-day classes years ago.

Schools that previously used federal or local dollars to provide full-day classes, mainly to low-income students, now have the potential to shift that money to summer school or new other programs. About 85 of Oregon's 170 districts provided full-day classes to all 5-year-olds prior to this year.

Middle-income families, who otherwise might pay as much as $3,600 in tuition for all-day kindergarten or for private half-day daycare, caught a break.

Most importantly, educators say, every 5-year-old now has access to a full day of structured learning at an age when brains are primed to learn. Research indicates they are sure to arrive at first grade better at reading and math, and likely more confident as learners too.

Past studies indicate those gains will evaporate by second or third grade. But Oregon school leaders are betting they can defy that old pattern and translate kindergarten gains into stronger third-grade reading skills.

Schools are not required to offer more than half a day of kindergarten, but they forfeit their share of the new millions if they don't. The Oregonian/OregonLive, with help from the state school boards association and state education department, searched extensively for half-day classes still operating in the state but found not one.

Parents applaud the profound change.

Tara Green, a Beaverton mom of two and co-president of the Scholls Heights Elementary parents organization, ticks off the benefits of a full day in class: "There is the routine. There is the social aspect of it, the relationship-building. It's a structured day. They learn a lot."

In Oregon, free is proving an attractive price for full-day classes, even in high-income areas. Kindergarten enrollments shot up more than anticipated in Lake Oswego, in Beaverton and in the Ainsworth neighborhood of in Portland's Southwest Hills, school officials report.

Curriculum directors and kindergarten teachers say half-day classes were too rushed and too shallow. That's especially true now that students are expected to read short books – and write them too – by the end of kindergarten.

In a six-hour school day, lessons on those skills and math go into much greater depth and allow for more practice, teachers say. Being together as a class all day also permits more attention to skills now regarded as important as the ABCs – cooperation, patience, perseverance and anger control.

Research provides mixed evidence about the long-term impact of all-day kindergarten.

Studies firmly establish that students learn far more from the full-day classes and start first grade performing better. But researchers also have found the boost that children receive from full-day K fades completely by second or third grade.

The new Common Core standards have led Oregon schools to greatly improve the alignment of primary school reading, writing and math instruction from grade to grade, educators say. Schools also have amped up expectations.

Those improvements, educators say, mean the extra learning kindergartners get from moving to full-day classes allows first grade teachers to begin the year at a more advanced level. That can lead to a more advanced second grade, and so on.

"We have the potential to really challenge that assumption" that the early gains from full-day K will inevitably disappear over the years, Noor said.

That will only happen, however, if Oregon schools maintain and expand the extra help they offer students who need extra help, primarily in the form of extra learning time, Twain said.

"Full-day kindergarten is not a silver bullet that is all we need to do," Cooper agreed.

Summer school is among the best strategies to help students who are furthest behind add to their skills, rather than see them erode, before they start the next grade, both said.

"We can't work so hard in full-day K and then not offer opportunities to our kids in the summer, particularly our neediest populations," Twain said.

No more 'drive-by' teaching

For 19 years, Paula Nelson taught half-day kindergarten. Then last year, Nelson got to experience at Lynch View Elementary what most Oregon kindergarten teachers will this year: She taught the same group of 5- and 6-year-olds six hours a day.

She would never go back.

"The biggest difference is the authenticity. You can do real teaching, not just a drive-by," she said.

Her students did full-blown writer's workshops, sharing their writing daily and helping edit each other's work. They sang more and got an extra music class each week. They didn't just read about spiders; they made them. With good behavior emphasized all day long, problem behavior rarely occurred.

Even parents seemed to value the full-day classes more. Student attendance was better than when she taught half days, Nelson said.

She didn't drill children on reading most of the day, as happens in many half-day classes, she said. She held reading groups when her pupils' concentration was at its peak.

At the end of the year, most of her students were reading at a mid-first-grade level.

Welcome back to school! This is an exciting time for students and parents as the 2018-2019 school year is fully under way. My name is Debbie Thibodeaux, President of the Oregon Virtual Public Schools Alliance (OVPSA) and learning coach to my own three children, ages 9, 14 and 16. OVPSA is a coalition of Oregon virtual public school families and supporters dedicated to the long-term viability of virtual public schools in our state.